RATCHET CLAMPING SYSTEM - John Jason Fallows

I am currently working on a prosthesis project that would allow children with agenesis to ski.

To ensure that the ski pole is attached to the prosthesis, I modelled a wheel clamping system.

This is the system I am presenting to you. I didn’t invent anything but after searching in vain for a solution on sites offering printable 3D files, I didn’t find anything adaptable according to my requirements.

This device was used for a great project of electronically assisted hand.

You can see an example at this link:

https://www.gre-nable.fr/en/electrically-assisted-flexibone-hand/

The principle is simple, you turn the knob clockwise and the coil inside winds the cord. The pawls hold the coil and prevent it from rotating in the opposite direction.

To loosen the cord, simply pull the knob and the coil will be released.

You can adapt this device to your own needs. It is only a first draft that is being improved but is working very well.

I used PLA and a 0.4mm nozzle.

This system consists of a mechanical system with low tolerances. I therefore recommend printing all parts with a layer height of 0.1mm.

For the ratchet part I added a stl file with a support offset by 0.3mm to facilitate printing (to be printed without additional support).

The two parts to be glued are the circular spring inside the knob and the pattern on the top of the knob that you can print in the color of your choice.

The pawl is inserted into the circular spring by means of the three tabs.

The spacer must be inserted between the ratchet disc and the circular spring.

The corp_2 part for fixing with M3 screws.

The piece corp_3 for sewing fixation.

Use a 20mm M3 screw and an M3 hexagonal nut to close it all.

For the cord follow the attached pictures.

Before final assembly, check that the spacer on the spring and ratchet disc is sliding correctly.

I am currently working on a project for a prosthesis that would allow children with agenesis to ski.

In order to secure the ski pole to the prosthesis, I modelled a knurled clamping system.

That’s the system I’m presenting to you. I didn’t invent anything but after searching in vain for a solution on sites offering printable 3D files, I didn’t find anything adaptable to my requirements.

This device has been used for a great electronic assisted hand project.

You can see an example by following this link:

https://www.gre-nable.fr/main-assistee-electriquement-flexibone/

The principle is simple, you turn the knob clockwise and the reel inside winds up the cord. The pawls hold the spool and prevent it from turning in the opposite direction.

To loosen the cord, simply pull the knob to release the spool.

You will be able to adapt this device to your own needs. This is only a first draft which is being improved but works very well.

I used PLA and a 0.4mm nozzle.

This system consists of mechanics with small tolerances. I therefore advise to print all parts with a layer height of 0.1mm.

For the ratchet part I added an stl file with 0.3mm offset support to facilitate printing (to be printed without additional support).

The two pieces to be glued are the circular spring inside the wheel and the pattern on top of the wheel that you can print in the colour of your choice.

The pawl is embedded in the circular spring thanks to the three tongues.

The spacer must be inserted between the ratchet disc and the circular spring.

The body part_2 for fixing with M3 screws.

The body part_3 for sewing attachment.

Use a 20mm M3 screw and an M3 hex nut to close it.

For the cord follow the attached pictures.

Before final assembly, check that the spacer slides smoothly over the spring and the ratchet disc.

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This article was first featured at https://cults3d.com/en/3d-model/various/younes-2 on March 6, 2021 at 08:19PM by